Phos Hilaron (Φῶς ἱλαρὸν) is an ancient Christian hymn originally written in Koine Greek. The hymn is known in English as 'Hail Gladdening Light,' or 'O Gladsome Light.' It is the earliest known Christian hymn, recorded outside of the Bible, that is still being used today. The hymn is featured in the Vespers of the Orthodox Church.
The song is first recorded by an unknown author in the Constitutiones Apostolicae which was written in the late 3rd or early 4th century A.D. It is found in a collection of songs to be sung in the morning, in the evening, before meals, and at candle lighting. Phos Hilaron is to be sung at the lighting of candles in the evening and so is sometimes known as the 'Candle-light Hymn'. Despite some of the words to the other three songs being from Scripture or in one case dated to around 150 AD, Phos Hilaron is the first to be considered an actual hymn in the modern sense. It is certainly the first complete example. It is far more rhythmic than the others and is divided into twelve verses varying between five, six, eight, nine, ten and eleven syllables a verse. Basil the Great (ca. 330 - January 1, 379) spoke of the singing of the Phos Hilaron as a cherished tradition of the church, the hymn being already considered old in his day (though some attribute the composition of the song to St Basil himself).
At that time in Jerusalem a candle was kept perpetually burning in the empty tomb of Christ, its glow a symbol of the living light of Jesus. As Christians gathered to worship the hymn was sung and, in a tradition known as the lighting of the lamps, the candle was brought forth from the tomb, its bright, solitary flame calling the church to celebrate the risen Lord.
Athenogenes, a saint of unknown date but is commemorated 16th July, is believed by some to have composed this hymn on the way to being martyred. He is often depicted as an elderly bishop with the executioner's arm paralyzed until the saint has completed his song. The Roman Martyrology states: "In Pontus, the birthday of Saint Athenogenes, [is celebrated, he was] an aged theologian, who, when about to consummate his martyrdom by fire, sang a hymn of joy, which he left in writing to his disciples." He is probably identical to the bishop who suffered at Sebaste, Armenia, with ten disciples under Diocletian on July 16; therefore estimating his death as around 305 A.D. However, Basil the Great notes the "ancient form" of this hymn, states it comes from antiquity, and states that it is of unknown origin immediately prior to mentioning the story of "the Hymn of Athenogenes, which, as he was hurrying on to his perfecting by fire, he left as a kind of farewell gift to his friends." Basil the Great is clearly stating that Athenogenes wrote a different hymn, which scholars believe to be "Δόξα ἐν ὑψίστοις" (Glory to God in the highest), a.k.a. the Great Doxology.
St. Sophronius I of Jerusalem (634-638 A.D), who was known for his poetry, is believed to have revised the hymn.
Φῶς ἱλαρὸν ἁγίας δόξης, ἀθανάτου Πατρός, οὐρανίου, ἁγίου, μάκαρος, Ἰησοῦ Χριστέ, ἐλθόντες ἐπὶ τὴν ἡλίου δύσιν, ἰδόντες φῶς ἑσπερινόν, ὑμνοῦμεν Πατέρα, Υἱόν, καὶ ἅγιον Πνεῦμα Θεόν. Ἄξιόν σε ἐν πᾶσι καιροῖς, ὑμνεῖσθαι φωναῖς αἰσίαις, Υἱὲ Θεοῦ, ζωὴν ὁ διδούς, Διὸ ὁ κόσμος σὲ δοξάζει.
English Lyrics - OCA
O Gladsome Light of the holy glory of the Immortal Father, heavenly, holy, blessed Jesus Christ. Now we have come to the setting of the sun and behold the light of evening. We praise God: Father, Son, and Holy Spirit. For it is right at all times to worship Thee with voices of praise, O Son of God and Giver of Life, therefore all the world glorifies Thee.